This invention relates broadly to the field of cellular telephones and particularly to the field of power management in cellular telephones.
Cellular telephones have become increasingly common communications devices used by individuals to permit communication with others while the caller is away from his/her cable connected telephone. Cellular telephones permit callers to contact others while walking from one office to another, while shopping or driving. The convenience of utilizing a cellular phone is the primary attraction of this form of communications device.
Cellular telephones also offer advantages in under developed nations where the wire/fiber infrastructure for telephones has not yet been installed or, due to physical conditions locally, cannot be installed economically.
No matter where the user attempts to use a cellular telephone, the device is usually operative only if there is power available in the battery that powers the phone. Hence, the user is required to periodically charge the battery to insure that sufficient power is available to operate the phone for a period of time that is dependent on the type of use. Accordingly, cell phone manufacturers typically will provide guidelines to the user as to the extent of xe2x80x9ctalk timexe2x80x9d and xe2x80x9cstandby timexe2x80x9d available.
xe2x80x9cTalk timexe2x80x9d is the amount of time a user can talk on the phone and fully consume the power available in the battery. This is frequently an average time as the actual time typically will vary somewhat due to the conditions of use. For example, CDMA phones in particular are operated at varying transmitter power levels. Hence, a CDMA phone could be operated entirely within a cellular network at locations where the transmit power levels required were at the maximum. If this were the case, the available talk time would be less than would be achieved if the phone were operated entirely in a region where transmit power levels were at a very low level.
xe2x80x9cStandby timexe2x80x9d refers to the time that a cell phone can be operated in the xe2x80x9conxe2x80x9d state where the phone is able to receive or originate a call so as to permit communication between another party and the cell phone user.
Manufacturer""s typically provide ratings for maximum xe2x80x9ctalk timexe2x80x9d and maximum xe2x80x9cstandby timexe2x80x9d. This data can be useful in comparing one cell phone with another or the capacity of different batteries for a given cell phone. However, it is not particularly useful after the phone has been used for a period of time in helping the user know how much power remains in the battery.
To overcome this issue, cell phone manufacturers usually provide some form of battery power indication. In some cases, the indicator takes the form of a bar graph depicting the power remaining in the battery. In other forms, an icon of a battery is shown which has bars inside, the number of bars being indicative of the amount of battery charge available. The difficulty with these forms of battery display is that they are frequently not very accurate and they do not really give the user any idea of whether the upcoming expected use of the phone can be achieved with the remaining battery power.
Another problem associated with the existing cell phone battery power available indicators is that they are generally unavailable to the user without the phone being activated and in the standby mode. Typically, the cell phone must be turned on and have completed the necessary communication with the cell phone service provider network before the battery life indicator becomes active and available to the user. Hence, a great deal of power is consumed from the battery by the registration process that occurs when a cell phone is powered on and thereafter becomes connected to the service provider network. In the event that the user is only attempting to determine the state of the battery, the power drain caused by registration is completely unnecessary. In addition, there is a cost to the cellular service network in that resources are allocated to the phone seeking to register which may not need to be allocated if the user powers off once the battery status is determined, a condition which occurs quite frequently.
In view of the above mentioned problems relating to battery power indicators in cell phones, it is a principal objective of the present invention to provide a battery power indicator that will provide a power available indicator to the user while minimizing the use of power from the phone itself.
It is a further objective of the present invention to provide a battery power indicator for a cell phone that will provide the user with more useful information as to the power available from the battery than is currently available.
It is another objective of the present invention to provide a battery power indicator for a cell phone that is available to the user and does not require the expendature of power and resources by a cellular network provider.
The above mentioned and other objects, advantages and features of the present invention are achieved by modification to typical cell phones. During the power on sequence that is activated when a cell phone is turned on, a test is performed to determine if a key, such as the # key, is depressed at the same time as the power on key. When this situation is detected, the cell phone executes a different power on sequence that results in activating the battery condition indicator. This indicator remains in the active state for a selected period of time and then the phone is turned off automatically thereby saving battery power and cellular network resources. The battery indicator of the present invention additionally provides the user with a better indication of the power available than the battery indicators frequently found in typical conventional cell phones. The present indicator provides a graphical representation of available power that easily translates into available talk and standby time.